As part of the U.S. Environmental Protection Agency's (US EPA) ongoing National Clean Diesel Campaign, the EPA has adopted new standards that dramatically reduce emissions of nitrogen oxide (NOx), diesel particulate matter (PM), unburned hydrocarbon (HC), and carbon monoxide (CO) from locomotive and marine diesel engines. Engines produced from 2005 to 2010 must meet US EPA Tier 2 standards, while engines produced from 2011 to 2014 must meet US EPA Tier 3 standards and engines produced from 2015 and beyond must meet US EPA Tier 4 standards. It is noted that engines produced prior to 1973 were uncontrolled while engines produced from 1973 to 2001 were required to meet US EPA Tier 0 standards and engines produced from 2002 to 2004 were required to meet US EPA Tier 1 standards.
While these EPA standards primarily relate to new and remanufactured engines, there is increasing pressure to reduce emissions of all existing non-road diesel engines. Eventually, all existing locomotive engines produced prior to 1973 must meet the US EPA Tier 0 standards and potentially even lower emission levels. For locomotives operating in specific emissions-regulated locations including California and Texas, emission levels must be reduced further with agreements to encourage the use of engines that meet the US EPA Tier 2 standards.
EMD produced more than 70,000 engines and has the largest installed base of diesel-electric locomotives in both North America and internationally. Among the two-cycle diesel engines produced by EMD are the EMD 567 series which was produced from 1938 until 1966 and the EMD 645 series which was produced from 1965 until 1988. The EMD 710 series which was produced from 1985 and is still produced currently. The EMD 567/645/710 engines can be used for long periods of time due to their ability to be repeatedly repaired/overhauled and the high cost of newly purchased engines.
There is a large population of EMD 567/645/710 engines in service that have not reached the end of their useful life—a unique feature of this engine segment compared to smaller engine models. Some existing engines may exceed fifty years of age. Because of the emission standards, however, the owners of these EMD 567/645/710 engines are faced with the option of either overhauling or rebuilding the engines to meet the newer emission standards or retiring the engines early and purchasing new technology engines that meet the current emission standards. As a result, the owners of these engines stand to incur a heavy financial loss. Accordingly, there is a need for a cost effective system and method for extending the useful life of these two-cycle diesel engines without requiring an expensive overhaul or new replacement engine.
One method for reducing the emissions on these engines involves the installation of electronic fuel injection. The current system utilizes mechanical injection where the injection is determined based on machined dimensions that are fixed, and do not vary during the use of the product. Electronic injection allows flexibility by varying the injection based on numerous inputs. Some of these inputs may include ambient temperature, altitude, geographic location, and so forth. Since the injectors are no longer fixed mechanically they require input from the engine as to the speed and position of the drive-train to determine with accuracy the time to begin, hold, and end, injection. New engines with electronic fuel injection incorporated in to the design utilize the flywheel for the monitoring and measurement of speed and RPM. The utilization of a once per revolution sensor to sense the absolute position, and then the monitoring of the flywheel teeth for synchronizing the position during the revolution is done utilizing two sensors on the flywheel. The concern with this prior art is that the sensors have a history of being damaged and moved due to their location in an area of the engine that is frequently accessed by mechanics. Accordingly, there is a need for an accurate device for monitoring and measuring the speed and position of these two-cycle diesel engines that can be easily installed in a retrofit or new application and in a position for reliable operation.